Refrigerating apparatus



- Aug. 7, 1956 R. M. SMITH REFRIGERATING APPARATUS Filed April 12, 1952 2 INVENTOR.

ROIf M. Smith '2,7s7,sss=- REFRIGERATING APPARATUS Rolf M. Smith, Dayton, ohio assignorto General Motors Corporation, Dayton, Ohio, a corporation of Delaware Application April 12, 1952-, Sesame. 282,019.

1 Claim. or. 230-207 This invention relates to refrigerating apparatus and more particularly to means for separating lubricant from refrigerant in such apparatus.

In refrigerating systems there is a tendency for the refrigerant in passing through the compressor to pick up lubricant in the compression chamber and to carry it through the refrigerating system. This often has caused the collection of lubricant in o'bjectional amounts in the condenser and the evaporator of the system. Various forms of separating means have been devised for separating lubricant from refrigerant especially between the compressor outlet and the condenser inlet. These separators usually relied on a change in the direction of flow to throw the lubricant out of the refrigerant.

It is an object of my invention to provide a simple effective device for separating lubricant from refrigerant especially in the compressor casing.

It is another object of my invention to provide a simple rotating device for contacting the lubricant and by centrifugal effect separating the lubricant from the refrigerant.

It is another object of my invention to provide a simple device for causing the mixture of refrigerant and lubricant to pass between closely spaced rotating surfaces.

These objects are attained by providing within the compressor casing a sleeve arrangement directly connected to the compressor shaft. This sleeve arrangement extends adjacent the outlet of the casing and is provided with perforations surrounding which there are a plurality of closely spaced discs.

The refrigerant and lubricant in passing to the outlet of the casing is forced to pass between the closely spaced rotating discs. The lubricant tends to collect on the disc and be thrown outwardly by centrifugal action while the refrigerant flows into the sleeve arrangement and thence to the outlet of the casing. The lubricant collects in the bottom of the casing and is returned to the working parts of the compressor by a pum or other suitable means.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred form of the present invention is clearly shown.

In the drawing:

The figure shows a rotary refrigerant compressor embodying one form of my invention together with the remaining parts of a refrigerating system illustrated in diagrammatic form.

Referring now to the drawing there is shown a compressor 20 having compressing means 22 driven by some suitable driving means through a drive shaft 24 which protrudes from the compressing means 22. Mounted upon the compressing means 22 is a sealed casing 26. The compressing means 22 has an inlet 28 connected to the outlet of an evaporating means 30, while the outlet 32 of the compressing means discharges into a discharge chamber 34 which is formed by a thin sheet metal casing 36 at one side of the compressing means 22 within the casing 26. The refrigerant flows out of the chamber 34 through passages (not shown) extending on either side 2,757,858 Patented. Aug 7, 1956 of (the outlet 32 and thence flows through thepassage 38 between the inner casing 36 and the outer casing 26.

The extension 40 of the drive shaft 24 within the casing 26 :is pro vided with an eccentric. portion 42 which cooperates with a reciprocating vane to .forma lubricant pump. This lubricant pump draws, in lubricant.throughv a lubricant inlet 44 in the bottom, of thecasing 26. The. eccentric portion 42 pumps this lubricantthroughout the. bearing surfacesof ,the compressing means22. Theex-.

tension 40 of the drive .shaft 24 is also provided with a thrust disc 46 operating between the thrust bearing members 48 on its opposite faces for preventing axial movement of the drive shaft. The extension 40 of the drive shaft 24 is also provided with a counterbalancing weight 50 which is enclosed in a cylindrical sheet metal cover 51 concentric with the axis of rotation of the drive shaft 24. This cover is fastened by screws to the end portion of the inner casing 36.

In the pumping of the refrigerant from the inlet 28 to the outlet 32 in the compressing means 22, some of the lubricant is picked up and carried along by the refrigerant. To keep as much as possible of the lubricant in the casing 26, a sleeve 52 is held within the counterbalance 50 by the washer 54 and the screw 56 at the end of the extension 40 of the drive shaft 24. This sleeve 52 is connected to a thin metal disc 58. Connected to the disc 58 by riveting or other suitable means is a second sleeve 60 provided with perforations 62. The disc 58 is located on one side of the perforations 62 and a second disc 64 is located on the opposite side of the perforations 62. Between the discs 58 and 64 is a third disc 66. These discs have a centrally located opening which surrounds the sleeve 52 and 60. The compressor casing 26 is provided with an outlet fitting 63 opposite the adjacent end of the drive shaft 24. This outlet fitting 68 has fastened to it a disc 70 having a centrally located aperture provided with a flange extending into the adjacent portion of the sleeve 60. This disc 70 prevents drops of lubricant running down the walls of the casing 26 from flowing into the outlet fitting 68.

The outlet fitting 68 is connected by the tube 72 to the condenser 74 which discharges into the receiver 76. From the receiver the liquid refrigerant flows under the control of a suitable type of refrigerant expansion device or valve 7 8 to the evaporator 30.

Accordingly, when the refrigerant with some lubricant is discharged from the outlet 32 some of the lubricant may drop directly into the bottom of the chamber 34 if it is sufficiently cooled. If the refrigerant and lubricant are quite warm they are cooled by being forced to pass through the passage 38 in direct contact with the casing 26 so that some cooling will take place. The lubricant will then be substantially all in liquid form while the refrigerant will be in the form of a gas. By being forced to pass between the discs 64, 66 and 58 the drops of lubricant will collect on these discs and be thrown out by centrifugal force against the walls of the outer casing 26 as the compressor operates. The lubricant so thrown out will collect in the bottom of the compressor casing 26 as illustrated by the reference character 80. The refrigerant stripped of the lubricant will pass to the center of the discs and through the apertures 62 and through the outlet fitting 68 to the conduit 72. In this way substantially all of the lubricant is kept within the compressor casing 26 and an adequate supply is insured at all times. This prevents any substantial amount of lubricant from circulating through. the system.

While the form of embodiment of the invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, as may come within the scope of the claim which follows.

What is claimed is as follows:

A compressor including a casing having an inlet and an outlet, at compressing means having its inlet connected to the inlet in said casing and having its outlet discharging into the interior of said casing, the interior of the casing forming a lubricant reservoir, the compressing means having its drive shaft located in coaxial relationship with the outlet of said casing, a sleeve means having an open end extending over and surrounding the mouth of the outlet of said casing, the opposite end of said sleeve means being closed, the side Walls of said slee e means being provided with perforations, said sleeve means being connected to and rotated by said drive shaft for keeping the lubricant in said casing While the discharge from the compressor passes through the outlet of said casing.

UNITED STATES PATENTS Riebel et al. Feb. 25, Erling July 14, Trask Dec. 22, Steenstrap Dec. 22, Sateren Nov. 7, Fulcher Dec. 14,

FOREIGN PATENTS Germany Mar. 27, Germany Dec. 13, 

